Railroad track grading method and machine



June 2, 1964 F. PLASSER ETAL 3,135,223

RAILROAD TRACK GRADING METHOD AND MACHINE Filed Dec. 21, 1960 2 Sheets-Sheet 1 FIG! INVENTORS WW2 A5FR y JOSE'F WQR Q June 2, 1964 F. PLASSER ETAL 3,135,223

RAILROAD TRACK GRADING METHOD AND MACHINE Filed Dec. 21, 1960 2 Sheets-Sheet 2 E :1. E; E

29 /IV a L 2 INVENTORS 670224552;

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United States Patent Ofi ice 3,135,223 Patented June 2, 1964 3,135,223 RAILROAD TRACK GRADING METHOD AND MACHINE Franz Plasser and Josef Theurer, both of Johannesgasse 3, Vienna I, Austria Filed Dec. 21, 1960, Ser. No. 77,417 7 Claims priority, application Austria Dec. 31, 1959 I 4 Claims. (Cl. 104-4) The present invention relates to railroad track grading operations, and more particularly to improvements in a method for simultaneously lifting a track to a desired level and fixing it at this level as well as in a combined track lifting and ballast tamping machine.

Combined track lifting and ballast tamping machines are known, as exemplified by US. Patent No. 2,734,463. In machines of this type, the track tamper itself carries track jacking means for lifting the track to a desired level and for holding it there while the tamping tools fix the track at this level by tamping ballast under the ties of the raised track. Experience has shown that the quality of the tamping and particularly the durability of the corrected track level depends largely on the tamping depth, i.e. the depth to which the tamping tools are immersed in the ballast during the tamping. The lifting stroke varies considerably from location to location, depending on the amount of correction necessary to obtain the desired track level, and may be as little as one millimeter and as much as six centimeters, for instance. If the support for the tamping tools during the tamping were vertically fixed in relation to the carriage, it would be impossible to obtain optimum results because the tools would be most deeply immersed in the ballast if the lifting stroke were smallest and vice versa. This is exactly contrary to the operational requirements because the greatest tamping depth is needed when the lifting stroke is largest to tamp suflicient ballast under the tie while it is best to tamp only superficially when the lifting stroke is small so that the deeper strata of the ballast, which have been compacted by the traffic rolling over the track, remains undisturbed.

In our US. Patent No. 2,876,709, we have disclosed a track tamping machine comprising a vertically adjustable support means for supporting the tamping tool at different tamping depths. However, this machine comprises no track jacking means and the patent fails to teach any concept leading to the vertical adjustment of the tamping tool support during the tamping operation in response to the lifting stroke of atrack jack.

It is the primary object of the present invention automatically to adjust the tamping depth in response to the lifting stroke in a track grading operation in which the track is simultaneously lifted and fixed in position.

It is a concomitant object of this invention to improve the durability of such track grading by automatically increasing and decreasing the tamping depth in response to a corresponding increase and decrease of each individual lifting stroke.

It is also an object of the invention to provide an improved track lifting and ballast tamping machine for accomplishing these results.

The combined track lifting and ballast tamping machine of the invention comprises a carriage which travels on the track and whereon tamping tools are mounted. The tamping tools are supportable in different vertical positions constituting difierent tamping depths in the ballast by a vertically adjustable support means. Means is mounted on the carriage for lifting the track to a desired level and control means interconnects the track lifting means and the vertically adjustable tamping tool support means for adjusting the support means in response to the lifting stroke of the track lifting means.

In accordance with one preferred embodiment, the support means is an hydraulically operated support mounted on the carriage for engagement with the base member of a vertically movable carrier whereon the tamping tools are mounted.

In accordance with another preferred embodiment, the track lifting means is a hydraulic jacking means and a hydraulic control circuit supplies pressure fluid to the hydraulically operated support and to the jack means. The hydraulic circuit includes a pressure fluid conduit interconnecting the support and the jack means, and delivering the fluid required for the lifting stroke of the jack means from the support to the jack means whereby the support is automatically adjusted vertically downwardly as additional fluid is delivered to the jack means for an increased lifting stroke.

While the present state of the art will obviously enable men of ordinary skill to devise a variety of means for carrying out the herein disclosed concepts, the invention will become more apparent in the following description of a particularly simple embodiment thereof, as illustrated in the accompanying drawing, wherein FIG. 1 is a side view, partly in section, of the track lifting and ballast tamping machine; and

FIG. 2 is a front view, partly in section, of the track lifting means including the rail gripping jaws.

The illustrated track tamping machine is generally similar to that of our US. Patent No. 2,876,709 but the invention obviously is not limited to this specific tamper and has, as a matter of fact, nothing to do with the tamping means structure, except inasmuch as it forms part of the combination.

As shown in the illustrated tamper, it comprises a tamping tool carrier 3 which is slidably supported on posts 2 for vertical movement in relation to carriage 1. As is well known, this vertical movement of the tamping tool carrier makes it possible to remove the ends of the tamping tools from the range of the track when the carriage is advanced from one tamping location, i.e. a tie, to another and to immerse the tamping tools in the ballast during the tamping operation.

Eccenter shaft 6 is supported on carrier 3, the shaft axis 7 being parallel to the ties 5 supporting track 4 upon which the carriage travels on wheels 27. Upon rotation, shaft 6 imparts a reciprocating motion to tamping tool mounting arms 7, the pair of tamping tools 8, 8 being pivotally connected at their upper ends to the end of the mounting arms. Intermediate their ends, the tamping tools are linked to a pivot element 9 which enables the opposing tamping tools to be reciprocated in a direction parallel to the track, as indicated by the two-headed arrows, by any suitable mechanism, not shown, such as that of our abovementioned patent.

The ends of the tamping tools have jaws 10, 10 for increasing the pressure area of the tamping tools on the ballast.

The tamping position of the tamping tools and their corresponding tamping depth is adjustable. For this purpose, there is provided a vertically adjustable support means for the tamping tools. In the illustrated embodiment, this support means is a hydraulically operated support which is mounted on carriage 1 for engagement with the base member of carrier 3. The support consists of a piston rod 12, whichris moved into engagement with the underside of the tamping tool carrier to support the same during the tamping operation, and a hydraulic cylinder 11 fixedly mounted in the carriage, the piston 12' of the piston rod being glidably mounted in the cylinder and dividing the same into an upper and a lower chamber 11a and 11b, respectively.

Also mounted on the carriage is a trackjacking means which, in the illustrated embodiment, is a hydraulic jack comprising cylinder 23 glidably housing piston 24 whose piston rod 24' carries at its lower end a track clamping means 25, any conventional track lifting means being suitable for the purpose, such as the one shown in FIG. 2, which is like that of the inventors US. Patent No. 2,847,- 943. The invention is not concerned either with the tamping means structure, or with the vertically adjustable tamping tool support, or with the track lifting means, except inasmuch as they form part of the combination.

As shown in FIG. 2, piston rod 24 extends outside cylinder 23 and has fixed to its free end a pivot 29 mounting the arms 28, 28' of gripping or clamping jaws 25, 25' in the manner of pliers. The jaws are provided with friction linings 33 adapted firmly to engage the head of rail 4-. To operate the clamping jaw arms, fluid pressure cylinder 30 is pivoted at 32 to arm 28 and piston rod 31' is pivoted to arm 28' at 32'. A fluid conduit supplies pressure fluid to one chamber of the cylinder to actuate piston 31 against the bias of a spring in the other cylinder chamber.

In accordance with the invention, the tampingdepth, which is determined by the vertical position of support 12, is controlled in dependence on the lifting stroke, which is determined by the vertical position of piston 24. Therefore, control means is provided for interconnecting the track lifting means and the vertically adjustable tamping tool support means.

In the illustrated embodiment, this control means is part of an hydraulic control circuit which supplies pressure fluid to the support and jack means. As shown, the tamping tool carrier 3 is built as a tank for pressure fluid and an input conduit 17 leads from the tank to a pressure fluid supply pump 16 which delivers pressure fluid to output conduit under constant pressure. Conduit 15 leads to two-way valve 14 which, in the illustrated idling position, returns the fluid through idling line to the supply tank. A branch line 18 is mounted in the circuit and carries pressure relief valve 19 set to prevent the pressure in the circuit from exceeding a maximum limit. In the working position of valve 14, the output conduit 15 delivers pressure fluid to input line 13 which is connected to upper chamber 110: of cylinder 11 so that delivery of fluid will move piston 12' downwardly.

The lower chamber 11b of cylinder 11 is interconnected by conduit 21 with the lower chamber 23a of cylinder 23. Cylinder chambers 11b and 23a, as well as the interconnecting conduit, are filled with hydraulic liquid of constant volume. A check valve is mounted in conduit 21.

The illustrated control mechanism operates as follows:

When the carriage 1 has reached the illustrated position in which the pairs of opposing tamping tools are located symmetrically in relation to the tie to be lifted and fixed at the raised level, the rail clamping means is operated to grip the rails. Valve 14 is placed in its operative position to deliver pressure fluid to the upper chamber llaof cylinder 11, which causes piston 12' to displacehydraulic liquid out of lower chamber 11b and through conduit 21 into lower chamber 23a of cylinder 23 and thus to raise piston 24 against the bias of coil spring 26 mounted in the upper chamber of the lift cylinder. As more fluid is delivered to chamber 11a, piston 12' is lowered to produce an increased tamping depth for the tamping tools when the tamping tool carrier 3 is lowered into its operative position to rest on piston rod support 12. Simultaneously, the continued displacement of hydraulic fluid from lower hydraulic cylinder chamber 11b of the support into lower hydraulic cylinder chamber 23a of the track jack raises piston 24 to lift the track toward the desired level. When this level is reached, check valve 22 in connecting conduit 21 is closed manually or automatically in response to a level determining means (not shown) so that no fluid may flow through the conduit and the position of pistons 24 and 12' remains fixed. Thus, the adjustable tamping tool carrier support remains firmly fixed in position at the adjustedw level of the track and oflers a fixed support for the tamping tool carrier during the ensuing tamping operation, with the tamping depth depending solely on the lifting stroke. If this stroke was large to obtain a considerable level correction, the vertical position of piston 24 is relatively high and the position of piston 12 correspondingly low so that the tamping tools 8 enter deeply into the ballast with their tamping jaws 10. On the other hand, the tamping depth will be correspondingly shallow if the lifting stroke was only small.

After the tamping operation is completed, the rail gripping means 25 is disengaged from the rails, the check valve 22 is opened and the coil spring 26 returns the piston 24 with the rail gripping means into the original position, the pressure fluid in chamber 23a being displaced through conduit 21 into chamber 11b to move piston 12' upwardly. Valve 14 has meanwhile also been moved into the illustrated idling position so that the correspondingly displaced hydraulic fluid may flow from upper chamber 11a through conduits 13 and 20 back into the storage tank.

If desired, the rail gripping means 25 may be disconnected and the check valve 22 opened a little before completion of the tamping, the gradual lifting of the tamping tool carrier by the ascending support 12 being obtained by making. the coil spring 26 correspondingly strong and/or adding another coil spring with an upward bias in chamber 11b. This type of tamping on a gradually rising level produces a particularly favorable compaction of the ballast under the tie.

It will be clearly understood that the simple embodiment of the invention herein illustrated and described merely gives a structural concept and that many variationsand'modifieations may occur to the skilled in the art without departing from. the spirit and scope of this invention as defined in the appended claims.

What we claim is:

1. A combined track lifting and ballast tamping ma chine, comprising a carriage to travel on the track, tamp ing' tools vertically movably mounted on said carriage, vertically adjustable support means for supporting the tamping tools in different vertical positions constituting different tampingdepths in the ballast, the support means including a vertically movable member, means mounted on the carriage for lifting the track to a desired level, the lifting means also including a vertically movable member and control means interconnecting the track lifting means and the vertically adjustable tamping tool support means, the control. means raising the vertically movable lifting means member in response to the lowering of the vertical ly movable. support means member whereby the lifting stroke of the track lifting means increases in response to an increase in the tamping depth determined by the support means.

2. A combined track lifting and ballast tamping machine, comprisinga carriage to travel on the track; a carrier having a base member vertically movably mounted on.the carriage; tamping tools mounted on the vertically movable carrier; a vertically adjustablehydraulically operated support mounted on said carriage for engagement with the carrier base member whereby the tamping tools are supportable in dilferent vertical positions constituting different tamping depths in the ballast, said support including a vertically movable piston; means mounted on the carriage for lifting the track to a desired level, the lifting means including a vertically movable member and control means interconnecting the track lifting means and the hydraulically operated support, the control means raising the vertically lifting means member in response to the lowering of the vertically movable piston whereby the lifting stroke of the track lifting means increases in response to an increase in the tamping depth determined by the support.

3. A combined track lifting and ballast tamping machine, comprising a carriage to travel on the track; a carrier having a base member vertically movably mounted on the carriage; tamping tools mounted on the vertically movable carrier; a vertically adjustable, hydraulically operated support mounted on said carriage for engagement with the carrier base member whereby the tamping tools are supportable in different vertical positions constituting different tamping depths in the ballast, said support including a vertically movable piston, hydraulic jack means mounted on the carriage for lifting the track to a desired level, said jack means also including a vertically movable piston; and a closed hydraulic control circuit conduit maintaining a constant volume of pressure fluid between the support and jack means pistons, and interconnecting the hydraulically operated support and the hydraulic jack means, the conduit delivering the fluid required for the lifting stroke of the jack means as the hydraulically operated support is moved vertically downwardly and fluid is displaced from the support piston to the jack means piston.

4. The combined track lifting and ballast tamping machine of claim 3, further comprising a check valve in the pressure fluid conduit, said check valve being operable to prevent pressure fluid flow through said conduit.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A COMBINED TRACK LIFTING AND BALLAST TAMPING MACHINE, COMPRISING A CARRIAGE TO TRAVEL ON THE TRACK, TAMPING TOOLS VERTICALLY MOVABLY MOUNTED ON SAID CARRIAGE, VERTICALLY ADJUSTABLE SUPPORT MEANS FOR SUPPORTING THE TAMPING TOOLS IN DIFFERENT VERTICAL POSITIONS CONSTITUTING DIFFERENT TAMPING DEPTHS IN THE BALLAST, THE SUPPORT MEANS INCLUDING A VERTICALLY MOVABLE MEMBER, MEANS MOUNTED ON THE CARRIAGE FOR LIFTING THE TRACK TO A DESIRED LEVEL, THE LIFTING MEANS ALSO INCLUDING A VERTICALLY MOVABLE MEMBER AND CONTROL MEANS INTERCONNECTING THE TRACK LIFTING MEANS AND THE VERTICALLY ADJUSTABLE TAMPING TOOL SUPPORT MEANS, THE CONTROL MEANS RAISING THE VERTICALLY MOVABLE LIFTING MEANS MEMBER IN RESPONSE TO THE LOWERING OF THE VERTICALLY MOVABLE SUPPORT MEANS MEMBER WHEREBY THE LIFTING STROKE OF THE TRACK LIFTING MEANS INCREASES IN RESPONSE TO AN INCREASE IN THE TAMPING DEPTH DETERMINED BY THE SUPPORT MEANS. 